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- /*
- * Copyright 2006 The Android Open Source Project
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
- #include "src/xml/SkXMLParser.h"
- #include "expat.h"
- #include "include/core/SkStream.h"
- #include "include/core/SkString.h"
- #include "include/core/SkTypes.h"
- #include "include/private/SkTo.h"
- static char const* const gErrorStrings[] = {
- "empty or missing file ",
- "unknown element ",
- "unknown attribute name ",
- "error in attribute value ",
- "duplicate ID ",
- "unknown error "
- };
- SkXMLParserError::SkXMLParserError() : fCode(kNoError), fLineNumber(-1),
- fNativeCode(-1)
- {
- reset();
- }
- SkXMLParserError::~SkXMLParserError()
- {
- // need a virtual destructor for our subclasses
- }
- void SkXMLParserError::getErrorString(SkString* str) const
- {
- SkASSERT(str);
- SkString temp;
- if (fCode != kNoError) {
- if ((unsigned)fCode < SK_ARRAY_COUNT(gErrorStrings))
- temp.set(gErrorStrings[fCode - 1]);
- temp.append(fNoun);
- } else
- SkXMLParser::GetNativeErrorString(fNativeCode, &temp);
- str->append(temp);
- }
- void SkXMLParserError::reset() {
- fCode = kNoError;
- fLineNumber = -1;
- fNativeCode = -1;
- }
- ////////////////
- namespace {
- const XML_Memory_Handling_Suite sk_XML_alloc = {
- sk_malloc_throw,
- sk_realloc_throw,
- sk_free
- };
- struct ParsingContext {
- ParsingContext(SkXMLParser* parser)
- : fParser(parser)
- , fXMLParser(XML_ParserCreate_MM(nullptr, &sk_XML_alloc, nullptr)) { }
- void flushText() {
- if (!fBufferedText.isEmpty()) {
- fParser->text(fBufferedText.c_str(), SkTo<int>(fBufferedText.size()));
- fBufferedText.reset();
- }
- }
- void appendText(const char* txt, size_t len) {
- fBufferedText.append(txt, len);
- }
- SkXMLParser* fParser;
- SkAutoTCallVProc<skstd::remove_pointer_t<XML_Parser>, XML_ParserFree> fXMLParser;
- private:
- SkString fBufferedText;
- };
- #define HANDLER_CONTEXT(arg, name) ParsingContext* name = static_cast<ParsingContext*>(arg)
- void XMLCALL start_element_handler(void *data, const char* tag, const char** attributes) {
- HANDLER_CONTEXT(data, ctx);
- ctx->flushText();
- ctx->fParser->startElement(tag);
- for (size_t i = 0; attributes[i]; i += 2) {
- ctx->fParser->addAttribute(attributes[i], attributes[i + 1]);
- }
- }
- void XMLCALL end_element_handler(void* data, const char* tag) {
- HANDLER_CONTEXT(data, ctx);
- ctx->flushText();
- ctx->fParser->endElement(tag);
- }
- void XMLCALL text_handler(void *data, const char* txt, int len) {
- HANDLER_CONTEXT(data, ctx);
- ctx->appendText(txt, SkTo<size_t>(len));
- }
- void XMLCALL entity_decl_handler(void *data,
- const XML_Char *entityName,
- int is_parameter_entity,
- const XML_Char *value,
- int value_length,
- const XML_Char *base,
- const XML_Char *systemId,
- const XML_Char *publicId,
- const XML_Char *notationName) {
- HANDLER_CONTEXT(data, ctx);
- SkDebugf("'%s' entity declaration found, stopping processing", entityName);
- XML_StopParser(ctx->fXMLParser, XML_FALSE);
- }
- } // anonymous namespace
- SkXMLParser::SkXMLParser(SkXMLParserError* parserError) : fParser(nullptr), fError(parserError)
- {
- }
- SkXMLParser::~SkXMLParser()
- {
- }
- bool SkXMLParser::parse(SkStream& docStream)
- {
- ParsingContext ctx(this);
- if (!ctx.fXMLParser) {
- SkDebugf("could not create XML parser\n");
- return false;
- }
- XML_SetUserData(ctx.fXMLParser, &ctx);
- XML_SetElementHandler(ctx.fXMLParser, start_element_handler, end_element_handler);
- XML_SetCharacterDataHandler(ctx.fXMLParser, text_handler);
- // Disable entity processing, to inhibit internal entity expansion. See expat CVE-2013-0340.
- XML_SetEntityDeclHandler(ctx.fXMLParser, entity_decl_handler);
- static const int kBufferSize = 512 SkDEBUGCODE( - 507);
- bool done = false;
- do {
- void* buffer = XML_GetBuffer(ctx.fXMLParser, kBufferSize);
- if (!buffer) {
- SkDebugf("could not buffer enough to continue\n");
- return false;
- }
- size_t len = docStream.read(buffer, kBufferSize);
- done = docStream.isAtEnd();
- XML_Status status = XML_ParseBuffer(ctx.fXMLParser, SkToS32(len), done);
- if (XML_STATUS_ERROR == status) {
- XML_Error error = XML_GetErrorCode(ctx.fXMLParser);
- int line = XML_GetCurrentLineNumber(ctx.fXMLParser);
- int column = XML_GetCurrentColumnNumber(ctx.fXMLParser);
- const XML_LChar* errorString = XML_ErrorString(error);
- SkDebugf("parse error @%d:%d: %d (%s).\n", line, column, error, errorString);
- return false;
- }
- } while (!done);
- return true;
- }
- bool SkXMLParser::parse(const char doc[], size_t len)
- {
- SkMemoryStream docStream(doc, len);
- return this->parse(docStream);
- }
- void SkXMLParser::GetNativeErrorString(int error, SkString* str)
- {
- }
- bool SkXMLParser::startElement(const char elem[])
- {
- return this->onStartElement(elem);
- }
- bool SkXMLParser::addAttribute(const char name[], const char value[])
- {
- return this->onAddAttribute(name, value);
- }
- bool SkXMLParser::endElement(const char elem[])
- {
- return this->onEndElement(elem);
- }
- bool SkXMLParser::text(const char text[], int len)
- {
- return this->onText(text, len);
- }
- ////////////////////////////////////////////////////////////////////////////////
- bool SkXMLParser::onStartElement(const char elem[]) {return false; }
- bool SkXMLParser::onAddAttribute(const char name[], const char value[]) {return false; }
- bool SkXMLParser::onEndElement(const char elem[]) { return false; }
- bool SkXMLParser::onText(const char text[], int len) {return false; }
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